Needle injection catheters are used for the delivery of cells or other biologic or therapeutic materials into various internal organs including the heart. The needle component spans the length of the catheter and functions as a fluid transport lumen to transport an injectable material from the proximal end of the catheter to the distal end of the catheter where the needle tip acts to inject the material into the target tissue. In order to puncture the tissue, the needle must be extended from the catheter. It must be retracted and sheathed, however, in order to effectively deliver the end of the catheter to the target area. Thus, the use of needle catheters require that the ends of the fluid transport lumen, that is the needle tip and the injection luer fitting at the proximal end of the catheter, must be moved relative to each other.
In commonly used needle catheters, a handle shell surrounds a needle, a manifold, a septum and a fluid lumen. The fluid lumen interacts with a luer fitting at the proximal end of the handle where it is can be attached to a syringe containing cells or other biologic or therapeutic materials. The fluid lumen also interacts with the manifold and septum in the middle region of the handle at which point it is coupled to the needle. Once the distal end of a catheter is positioned at a target tissue, the needle is extended by moving the needle relative to the manifold and fluid lumen while a fluid tight seal is maintained by the septum. The needle is retracted by reversing the process. These systems, however, are costly, difficulty to manufacture and prone to leakage.
There is a need in the art, therefore, for novel needle catheter assemblies that are easy to manufacture and less prone to leakage.